Aliphatic polycarbonates (APCs) are biocompatible and biodegradable materials with numerous uses ranging from high-performance applications in material science to use as biodegradable consumer packaging. APCs having two carbon atoms separating the carbonate moieties are typically made by the copolymerization of an aliphatic oxide and CO2. Such polymerization reactions are typically initiated through the use of a catalyst, and therefore, require a quenching step to terminate the resulting copolymerization. Thus, there is a need for improved methods for making APCs and improved methods for quenching the copolymerization reaction that form such APCs.